body {
    font-family: Arial, sans-serif;
    margin: 20px;
}

.container {
    max-width: 600px;
    margin: 0 auto;
}

input, button {
    margin: 5px 0;
    padding: 10px;
    width: 100%;
}

.book-list {
    margin-top: 20px;
}

pre {
    background: #f4f4f4;
    padding: 10px;
    border-radius: 5px;
}